Sveltekit fetch action wrapper

fetchTools.ts

import type {ActionResult} from "@sveltejs/kit";
import {applyAction, deserialize} from "$app/forms";

export const fetchAction = async <Input, Output>(actionPath: string, data: Input): Promise<Output> => {

    const result: ActionResult = await fetch(actionPath, {
        method: 'POST',
        headers: {
            'x-sveltekit-action': 'true'
        },
        body: JSON.stringify(data)
    }).then(v => v.text()).then(v => deserialize(v));

    await applyAction(result);

    if(result.type === 'success'){
        return result.data as Output;
    }

    throw null;

}